PRC is going to be the biggest importer of crude oil.
Saudi Arabia knows that and yet crude is still priced in USD.
Aside from weapons, WMDs and Hollywood movies, PRC is the world's big exporter of everything from hand-cranked widgets to hi-tech robotics that control the whole loading and unloading at dockyards.
How will RMB weight into the basket of currencies, especially vis the Canadian dollar? The Twittermeister will regret reneging on NAFTA with Canada at some point, but then he won't be around and will probably be retired.
Going forward, will RMB weight heavier than USD in pricing for crude oil?

Oil is going to run out, then what? In my opinion it is sort-sighted to think that valuing oil in some other currency than USD will solve problems.

There are reasons why Saudis or others do not sell oil in RMB. PRC is still quite new and partially undeveloped country, and facing huge transformations in structures socially, economically and politically, and risks on both national and international level. Nobody wants to bet on PRC or their currency in this situation, at least not while the alternative is USD.